COFFER, in Fortification, denotes a hollow lodgement athwart a dry moat, from six to seven feet deep and from sixteen to eighteen broad; the upper part made of pieces of timber raised two feet above the level of the moat, which little elevation has hurdles laden with earth for its cover-
Coffin. ing, and serves as a parapet with embrasures. The coffer is nearly the same with the caponière; excepting that the last is sometimes made beyond the counterscarp on the glacis, and the coffer always in the moat, taking up its whole breadth, which the caponière does not. It differs from the traverse and gallery in this, that the latter are made by the besiegers, and the coffer by the besieged. The besieged generally make use of coffers to repulse the besiegers when they endeavour to pass the ditch. To save themselves from the fire of these coffers, the besiegers throw up earth on the side towards the coffer.